2" would be a complete waste if you ask me. Airflow goes down drastically as you lower pipe size. Do at least 2.5"

Both your options would add weight to the suspension itself but if its aluminum it would be minimal. I think getting under the car and looking at how much room you have for various options is your next step. Drive it up on ramps so you see how everything looks at ride height. Both would work decent but not as much total airflow as from the front. Personally if I were to do one I'd do the scoop mounted on the arm, the other method is tougher to get the air going exactly where you want..

The scoops look like an easy and cheap alternative but as a daily driver the scoops protrude too low for me. I would not feel safe on the street with them and since true ducts can be done fro $125 it isn't too much more than the cost of the scoops to make me feel more comfortable on the road.

Well, I bought a set of T4 bumper ports from Advanced Composites. More air flow into those than into the OEM fog light openings, and smoother air flow because of the curvature of the T4 opening. I think the front openings on the T4's are about 8" by 8", quite a bit bigger than the air ducts that others have been putting in behind the grilles. Plus, I think they look kinda cool. Pic below is from T4 install guide so you can see the difference in opening size.

If I can't get it to work for some reason, backup plan will be to use the spots on the lower grille like everyone else has, but that creates other headaches for me as I would have to move my CAI scoop somehow. I also don't like the idea of sucking air away from the front as I have a remote oil cooler down there and want to keep as much air as possible up there so it stays cool.

Let us know how it turns out. What brake setup you running for the track?

Will do!

Right now I am running Racing Brake slotted rotors up front, OEM out back, and Cobalt Friction XR4/2 pads. Long and sorry story of smoked pads and warped rotors at http://www.camaro5.com/forums/showth...294470&page=14 if you're interested in reading what ended me up with this setup, which I really like.

I was thinking the same thing, I feel a lot better with the front grill local especially given that a GM engineer recommended over the fog light location. I believe the air would be moving very fast under the splitter but 90 degrees to the opening whicj does not seem optimal. However I know nothing about fluid dynamIcs so who knows. I will stick with what works.

Got all the hose, clamps, etc. and the ACS T4 ducts. Yellow part fits in front, unpainted/black part sandwiches the bumper from the back. Also got two small black general purpose air ducts from Racer Parts Wholesale. Will have to butcher the small ducts to get them to fit on the back of the T4 plenum, but it will work. Will give me a nice mounting point for the hose, and channel air towards it, pointing back and down at a 45 degree angle. Going to start building the back assembly and getting the light bars installed, then hoping for warmer weather so I can do the cutting and gluing in the bumper (fumes means I need to do it outdoors, and can't do it when it's too cold).

Got all the hose, clamps, etc. and the ACS T4 ducts. Yellow part fits in front, unpainted/black part sandwiches the bumper from the back. Also got two small black general purpose air ducts from Racer Parts Wholesale. Will have to butcher the small ducts to get them to fit on the back of the T4 plenum, but it will work. Will give me a nice mounting point for the hose, and channel air towards it, pointing back and down at a 45 degree angle. Going to start building the back assembly and getting the light bars installed, then hoping for warmer weather so I can do the cutting and gluing in the bumper (fumes means I need to do it outdoors, and can't do it when it's too cold).